Hi jsch-
Great question.
True friends that I drank with to excess do not care that I am no longer drink, they didn't even ask "why" I quit 'cuz on far too many occasions they've seen me smashed, getting asked to leave from clubs and had to place me in taxis..... We still get together, have a great time and I stay sober...
Drinking buddies were just that, people I drank with... They still give me a hard time when I see them, but my sobriety has truly empowered me to dismiss it very quickly. I ALWAYS drank more than them, and perhaps they used me as an excuse for their excessive drinking - see - I did not get as hammered as him approach.
Friends put you in a taxi when you are wasted, drinking buddies leave you at the bar.